Confidence:StrongSolidPlausibleTentativeSpeculative

• Soul of Theros

  4WW

  Creature — AvatarW

  Damage + lifelink: lifelink converts damage on one side into life triggers the partner pays off — the canonical Heliod / Karlov family.
• Bramble Wurm

  6G

  Creature — WurmG

  Lifegain pair: one card gains life while the other rewards lifegain. They reinforce each other in a lifegain deck.
• Elixir

  1

  ArtifactC

  Lifegain pair: one card gains life while the other rewards lifegain. They reinforce each other in a lifegain deck.
• Baron Helmut Zemo

  BBB

  Legendary Creature — Human Noble VillainB

  Copy engine: one card makes a copy of a creature every turn, and the other's enter-the-battlefield effect rewards each copy. Real, repeatable value — the partner can't untap or re-enter the copier, so it never goes infinite.
• Chandra, Flameshaper

  5RR

  Legendary Planeswalker — ChandraR

  Copy engine: one card makes a copy of a creature every turn, and the other's enter-the-battlefield effect rewards each copy. Real, repeatable value — the partner can't untap or re-enter the copier, so it never goes infinite.
• Edea, Possessed Sorceress

  2UBR

  Legendary Creature — Human WarlockBRU

  Graveyard pair: one card brings creatures back from the graveyard repeatedly (or a creature that returns itself), and the other keeps feeding the loop — a recurring reanimator with a payoff, or a sacrifice outlet with a self-recurring creature.
• Valentin, Dean of the Vein // Lisette, Dean of the Root

  B2GG

  Legendary Creature — Vampire Warlock // Legendary Creature — Human DruidBG

  Both cards trigger on life gain — they fire together.
• Rinoa, Angel Wing

  2W

  Legendary Creature — Human Rebel WarlockW

  Graveyard pair: one card brings creatures back from the graveyard repeatedly (or a creature that returns itself), and the other keeps feeding the loop — a recurring reanimator with a payoff, or a sacrifice outlet with a self-recurring creature.
• Nazar, the Velvet Fang

  3B

  Legendary Creature — Vampire WarlockB

  Both cards trigger on life gain — they fire together.
• Karlov of the Ghost Council

  WB

  Legendary Creature — Spirit AdvisorBW

  Both cards trigger on life gain — they fire together.
• Amalia Benavides Aguirre

  WB

  Legendary Creature — Vampire ScoutBW

  Both cards trigger on life gain — they fire together.
• Trudge Garden

  2G

  EnchantmentG

  Both cards trigger on life gain — they fire together.
• Avatar Kyoshi, Earthbender

  5GGG

  Legendary Creature — Human AvatarG

  Graveyard pair: one card brings creatures back from the graveyard repeatedly (or a creature that returns itself), and the other keeps feeding the loop — a recurring reanimator with a payoff, or a sacrifice outlet with a self-recurring creature.
• Comforting Counsel

  1G

  EnchantmentG

  Both cards trigger on life gain — they fire together.
• Nephalia Smuggler

  U

  Creature — Human RogueU

  Blink pair: one card can blink creatures repeatedly, and the other's ETB rewards every re-entry. Free-running only when the blink is free or refunded (Deadeye + Drake class); otherwise a repeatable value engine.
• Soulherder

  1WU

  Creature — SpiritUW

  Blink pair: one card can blink creatures repeatedly, and the other's ETB rewards every re-entry. Free-running only when the blink is free or refunded (Deadeye + Drake class); otherwise a repeatable value engine.
• The Mind Stone

  1W

  Legendary Artifact — Infinity StoneW

  Blink pair: one card can blink creatures repeatedly, and the other's ETB rewards every re-entry. Free-running only when the blink is free or refunded (Deadeye + Drake class); otherwise a repeatable value engine.
• Mirrorhall Mimic // Ghastly Mimicry

  3U

  Creature — Spirit // Enchantment — AuraU

  One-shot copy enabler: a card enters as a copy of another (Phantasmal Image, Body Double, Phyrexian Metamorph), firing the partner's substantive ETB once. Not a repeating chain — fires once on entry — but valuable when the partner's ETB is combo-grade (graveyard reanimator, mana doubler, etc.).
• Prize Pig

  1G

  Creature — BoarG

  Both cards trigger on life gain — they fire together.
• Qala, Ajani's Pridemate

  3W

  Legendary Creature — Cat WarriorW

  Both cards trigger on life gain — they fire together.
• Xu-Ifit, Osteoharmonist

  1BB

  Legendary Creature — Human WizardB

  Recursion engine: one card can reanimate repeatedly (an activated ability), and the other is a creature worth bringing back again and again. Real, repeatable value — not an infinite loop on its own.
• Saheeli Rai

  1UR

  Legendary Planeswalker — SaheeliRU

  Copy engine: one card makes a copy of a creature every turn, and the other's enter-the-battlefield effect rewards each copy. Real, repeatable value — the partner can't untap or re-enter the copier, so it never goes infinite.
• Grenzo, Dungeon Warden

  XBR

  Legendary Creature — Goblin RogueBR

  Recursion engine: one card can reanimate repeatedly (an activated ability), and the other is a creature worth bringing back again and again. Real, repeatable value — not an infinite loop on its own.
• Junji, the Midnight Sky

  3BB

  Legendary Creature — Dragon SpiritB

  Graveyard pair: one card brings creatures back from the graveyard repeatedly (or a creature that returns itself), and the other keeps feeding the loop — a recurring reanimator with a payoff, or a sacrifice outlet with a self-recurring creature.
• Whip of Erebos

  2BB

  Legendary Enchantment ArtifactB

  Recursion engine: one card can reanimate repeatedly (an activated ability), and the other is a creature worth bringing back again and again. Real, repeatable value — not an infinite loop on its own.